package com.zjw.websocket.config;

import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.JSONObject;
import com.zjw.websocket.WebsocketApplication;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.boot.web.servlet.ServletContextInitializer;
import org.springframework.stereotype.Component;
import org.springframework.web.util.WebAppRootListener;

import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.websocket.*;
import javax.websocket.server.PathParam;
import javax.websocket.server.ServerEndpoint;
import java.io.IOException;
import java.util.HashMap;
import java.util.Map;
import java.util.Objects;
import java.util.concurrent.CopyOnWriteArraySet;

/**
 * @author zhaojinwei
 */

@ServerEndpoint("/websocket/{sid}")
@Component
public class WebSocketServer implements ServletContextInitializer {

    public WebSocketServer() {
        System.out.println("--------创建WebSocketServer--------");
    }

    private final static Logger log = LoggerFactory.getLogger(WebsocketApplication.class);
    /**
     * 静态变量，用来记录当前在线连接数。应该把它设计成线程安全的。
     */
    private static int onlineCount = 0;
    /**
     * concurrent包的线程安全Set，用来存放每个客户端对应的MyWebSocket对象。
     */
    private static CopyOnWriteArraySet<WebSocketServer> webSocketSet = new CopyOnWriteArraySet<>();

    /**
     * 与某个客户端的连接会话，需要通过它来给客户端发送数据
     */
    private Session session;

    /**
     * 接收sid
     */
    private String sid = "";

    /**
     * 连接建立成功调用的方法
     */
    @OnOpen
    public void onOpen(Session session, @PathParam("sid") String sid) {
        this.session = session;
        this.sid = sid;
        //加入set中
        webSocketSet.add(this);
        //在线数加1
        addOnlineCount();
        log.info("有新窗口开始监听:" + sid + ",当前在线人数为" + getOnlineCount());
        try {
            sendMessage(null, this, "连接成功");
        } catch (IOException e) {
            log.error("websocket IO异常");
        }
    }

    /**
     * 连接关闭调用的方法
     */
    @OnClose
    public void onClose() {
        //从set中删除
        webSocketSet.remove(this);
        //在线数减1
        subOnlineCount();
        log.info("有一连接关闭！当前在线人数为" + getOnlineCount());
    }

    /**
     * 收到客户端消息后调用的方法
     *
     * @param message 客户端发送过来的消息
     */
    @OnMessage
    public void onMessage(String message, Session session) {
//        JSONObject jsonObject = JSON.parseObject(message);
        log.info("收到来自窗口" + sid + "的信息:" + message);
//        //群发消息
        for (WebSocketServer item : webSocketSet) {
            try {
                item.sendMessage(this,item,message);
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }

    /**
     * 发生错误时调用
     *
     * @param session
     * @param error
     */
    @OnError
    public void onError(Session session, Throwable error) {
        log.error("发生错误");
        error.printStackTrace();
    }

    /**
     * 实现服务器主动推送
     */
    private void sendMessage(WebSocketServer from, WebSocketServer to, String message) throws IOException {
        Map<String, Object> msg = new HashMap<>(6);
        msg.put("from", from);
        msg.put("to", to);
        msg.put("message", message);
        this.session.getBasicRemote().sendText(JSON.toJSONString(msg));
    }


    @Override
    public boolean equals(Object o) {
        if (this == o) {
            return true;
        }
        if (o == null || getClass() != o.getClass()) {
            return false;
        }
        WebSocketServer that = (WebSocketServer) o;
        return Objects.equals(session, that.session) &&
                Objects.equals(sid, that.sid);
    }

    @Override
    public int hashCode() {
        return Objects.hash(session, sid);
    }

    public String getSid() {
        return sid;
    }

    public void setSid(String sid) {
        this.sid = sid;
    }

    /**
     * 群发自定义消息
     */
//    public static void sendInfo(String message,@PathParam("sid") String sid) throws IOException {
//        log.info("推送消息到窗口"+sid+"，推送内容:"+message);
//        for (WebSocketServer item : webSocketSet) {
//            try {
//                //这里可以设定只推送给这个sid的，为null则全部推送
//                if(sid==null) {
//                    item.sendMessage(message);
//                }else if(item.sid.equals(sid)){
//                    item.sendMessage(message);
//                }
//            } catch (IOException e) {
//                continue;
//            }
//        }
//    }
    private static synchronized int getOnlineCount() {
        return onlineCount;
    }

    private static synchronized void addOnlineCount() {
        WebSocketServer.onlineCount++;
    }

    private static synchronized void subOnlineCount() {
        WebSocketServer.onlineCount--;
    }

    @Override
    public void onStartup(ServletContext servletContext) throws ServletException {
        servletContext.addListener(WebAppRootListener.class);
        //配置websocket传输大小，50M
        servletContext.setInitParameter("org.apache.tomcat.websocket.textBufferSize", "52428800");
        servletContext.setInitParameter("org.apache.tomcat.websocket.binaryBufferSize", "52428800");
    }
}